Windows 8 SSD Optimize Feature Fails On ASMedia 1061 SATA Chipset?

I usually don't use the ASMedia SATA chipset ports (two chips/four ports on the ASRock Z97 Extreme 6 board) since they have caused issues for me in the past (and still do) but I tried them again recently and noticed a new issue.

Windows 8/8.1 has an SSD Optimize feature, a manual TRIM command function. I've used it on SSDs connected to the Intel SATA ports, and it works fine.

I recently tried the Optimize feature on two SSDs connected to the ASMedia SATA ports, an Intel 530 and Samsung 830. The Optimize function started, but then failed and the entry for both of the SSDs on the ASMedia ports said "Feature not available".

Has anyone else seen this behavior with SSDs and the ASMedia SATA chip with the Windows 8 SSD Optimize feature? The Intel 530 and Samsung 830 are two completely different SSDs, not sharing any components whatsoever. This behavior IMO makes me wonder about TRIM support on the ASMedia chip and driver pair, or with the chip in general.